Appearing to read from a script, the photo journalist describes himself as the "British citizen abandoned by my government".

He goes on to warn of an impending third war in the Gulf and accuses Western media of being complicit with America in trying to drum up support for a ground war against Isis.

"Obama is terribly busy insisting US ground troops won't be going back into Iraq. Thus even the Pentagon admits airstrikes are a stop-gap military measure that will not disrupt the Islamic State activities," he says.

Since when has America cared about the fate of a minority in the Muslim lands? Modern history is sadly littered with religious minorities being crushed and neither the U.S. nor anyone else said anything.

- John Cantlie

"Meanwhile, America puts 1,200 troops into Baghdad to protect their embassy and the airport. Surely sounds like boots on ground to me… The rise of the Islamic State give Obama a chance to look tough in the media just as midterm elections approach."

In the video, he suggests US President Barack Obama's concern regarding the plight of the Christian Yazidi minority who have been persecuted by Isis is entirely feigned.

"Since when has America cared about the fate of a minority in the Muslim lands? Modern history is sadly littered with religious minorities being crushed and neither the US nor anyone else said anything."

Later on in the video, Cantlie claims the public is wrong to support US led military air strikes against Isis.

"They [Isis] have grown exponentially so that even the US military, the policeman of the world, are not able to contain them. So we have spent a few trillion dollars on failed wars in Iraq and Afghanistan. Isn't it worth spending a few trillion more to avoid the spectre of another 9/11?"'

Isis militants have threatened that Cantlie is the next hostage to be executed following the recent beheadings of IS hostages David Haines, James Foley and Steven Sotloff.

Just two days ago Cantlie's sister Jessica issued an emotional appeal urging the militant group to "restart dialogue" with the captive's family.

Speaking directly to camera, Jessica said: "We, John's family, want to address Islamic State, who are holding him. It is not true to say that there has been no attempt to engage with IS. It is simply not accurate. This is frustrating for all parties, including those who are trying to assist us. We had previously been in contact through a channel started by you, but then this stopped for reasons best known to you."

Referring to her brother's appearance in the videos and article, Jessica said his 'words are powerful and have huge resonance'.

Her father, Paul Cantlie, had earlier issued an emotional video appeal for his son to be released describing him as a "good man who only wanted to help the Syrian people."

Cantlie's whereabouts are currently unknown, but it is likely he is being held in Syria at the location where hostages James Foley, Steven Sotloff and David Haines were believed to have been murdered in Isis's de-facto capital of Raqqa.